Man or Matter Part 23

If in this book we come somewhat late to a discussion of Goethe's colour-theory, in spite of the part it played in his own scientific work, and in spite of its significance for the founding of a physics based on his method, the reasons are these. When Goethe undertook his studies in this field he had not to reckon with the forms of thought which have become customary since the development of mechanistic and above all - to put it concisely - of 'electricalistic' thinking. Before a hearing can be gained in our age for a physics of Light and Colour as conceived by Goethe, certain hindrances must first be cleared away. So a picture on the one hand of matter, and on the other of electricity, such as is given when they are studied by Goethean methods, had first to be built up; only then is the ground provided for an unprejudiced judgment of Goethe's observations and the deductions that can be made from them to-day.

As Professor Heisenberg, in his lecture quoted earlier (Chapter II), rightly remarks, Goethe strove directly with Newton only in the realms of colour-theory and optics. Nevertheless his campaign was not merely against Newton's opinions in this field. He was guided throughout by the conviction that the fundamental principles of the whole Newtonian outlook were at stake. It was for this reason that his polemics against Newton were so strongly expressed, although he had no fondness for such controversies. In looking back on that part of the Farbenlehre which he had himself called 'Polemical' in the t.i.tle, he said to Eckermann: 'I by no means disavow my severe dissections of the Newtonian statements; it was necessary at the time and will also have its value hereafter; but at bottom all polemical action is repugnant to my nature, and I can take but little pleasure in it.'

The reason why Goethe chose optics as the field of conflict, and devoted to it more than twenty years of research and reflexion, amidst all the other labours of his rich life, lay certainly in his individual temperament - 'zum Sehen geboren, zum Schauen bestellt'.1 At the same time one must see here a definite guidance of humanity. Since the hour had struck for mankind to take the first step towards overcoming the world-conception of the one-eyed, colour-blind onlooker, what step could have been more appropriate than this of Goethe's, when he raised the eye's capacity for seeing colours to the rank of an instrument of scientific cognition?

In point of fact, the essential difference between Goethe's theory of colour and the theory which has prevailed in science (despite all modifications) since Newton's day, lies in this: While the theory of Newton and his successors was based on excluding the colour-seeing faculty of the eye, Goethe founded his theory on the eye's experience of colour.

In view of the present scientific conception of the effect which a prismatic piece of a transparent medium has on light pa.s.sing through it, Goethe's objection to Newton's interpretation and the conclusions drawn from it seems by no means as heretical as it did in Goethe's own time and for a hundred years afterwards. For, as Lord Rayleigh and others have shown, the facts responsible for the coming into being of the spectral colours, when these are produced by a diffraction grating, invalidate Newton's idea that the optical apparatus serves to reveal colours which are inherent in the original light. Today it is known that these colours are an outcome of the interference of the apparatus (whether prism or grating) with the light. Thus we find Professor R. W.

Wood, in the opening chapter of his Physical Optics, after having described the historical significance of Newton's conception of the relation between light and colour, saying: 'Curiously enough, this discovery, which we are taking as marking the beginning of a definite knowledge about light, is one which we shall demolish in the last chapter of this book,2 for our present ideas regarding the action of the prism more nearly resemble the idea held previous to Newton's cla.s.sical experiments. We now believe that the prism actually manufactures the coloured light.'

We find ourselves faced here with an instance of the problem, 'Discovery or Manufacture?' dealt with by Eddington in the manner described in our previous chapter. This very instance is indeed used by Eddington himself as a case in which the answer is definitely in favour of 'manufacture'. Nevertheless, Eddington complains, experts, in spite of knowing better, keep to the traditional way of speaking about the spectral colours as being originally contained in the light. 'Such is the glamour of a historical experiment.'3 It is for the same reason that Goethe's discovery continues to be unrecognized by the majority of scientists, who prefer, instead of examining the question for themselves, to join in the traditional a.s.sertion that 'Goethe never understood Newton'.

As Goethe relates at the conclusion of the 'historical' part of his Farbenlehre,4 he was drawn to study colour by his wish to gain some knowledge of the objective laws of aesthetics. He felt too close to poetry to be able to study it with sufficient detachment, so he turned to painting - an art with which he felt sufficiently familiar without being connected with it creatively - hoping that if he could discover the laws of one art they would prove applicable to others.

His visit to Italy, a land rich both in natural colour and in works of art, gave him a welcome opportunity to pursue this inquiry, but for a long time he made no headway. The paintings he saw suggested no inherent law in their arrangement of colours, nor could the painters he questioned tell him of one. The only qualitative distinction they seemed to recognize was between 'cold' and 'warm' colours.

His own observations led him to a definite experience of the quality of the colour blue, for which he coined the phrase 'feebleness of blue'

('Ohnmacht des Blau'). In some way this colour seemed to him to be related to black. In order to rouse his artist friends and to stimulate their reflexions, he liked to indulge in paradoxes, as when he a.s.serted that blue was not a colour at all. He found, however, as time went on, that in this way he came no nearer his goal.

Although the splendour of colour in the Italian sky and the Italian landscape made a powerful impression on Goethe, he found not enough opportunity for systematic study to allow him to arrive at more than a dim surmise of some law underlying the occurrence of colour in nature.

Still, there was one thing he took home with him as a result of his labours. He had grown convinced that 'the first approach to colours as physical phenomena had to be sought from the side of their occurrence in nature, if one would gain an understanding of them in relation to art'.

Back at home, he strove to recollect the theory of Newton as it was being taught in schools and universities - namely, that 'colours in their totality are contained in light'. Hitherto he had had no occasion to doubt the correctness of this theory. Like everyone else, he had heard it expounded in lectures as an incontestable result of empirical observation, though without this ever having been shown to him by way of experiment. He convinced himself by consulting a manual that his recollection was correct, but at the same time he found that the theory there set forth gave no help in answering his questions.5 So he decided to examine the phenomena for himself.

For this purpose he borrowed a set of prisms from a friend living in near-by Jena, the physicist, b.u.t.tner. Since, however, he had at that time no opportunity of arranging a dark chamber on Newton's lines, where the necessary ray of light from a tiny hole in the window-covering was sent through a prism, he postponed the whole thing, until in the midst of all his many other interests and duties it was forgotten. In vain b.u.t.tner pressed many times for the return of the prisms; at last he sent a mutual acquaintance with the injunction not to return without them.

Goethe then searched for the long-neglected apparatus and determined to take a rapid glance through one of the prisms before he gave them back.

He recalled dimly his pleasure as a boy at the vision of the world given him through a bit of similarly shaped gla.s.s. 'I well remember that everything looked coloured, but in what manner I could no longer recollect. I was just then in a room completely white; remembering the Newtonian theory, I expected, as I put the prism to my eye, to find the whole white wall coloured in different hues and to see the light reflected thence into the eye, split into as many coloured lights.

'But how astonished was I when the white wall seen through the prism remained white after as before. Only where something dark came against it a more or less decided colour was shown, and at last the window-bars appeared most vividly coloured, while on the light-grey sky outside no trace of colouring was to be seen. It did not need any long consideration for me to recognize that a boundary or edge is necessary to call forth the colours, and I immediately said aloud, as though by instinct, that the Newtonian doctrine is false.'

For Goethe, there could be no more thought of sending back the prisms, and he persuaded b.u.t.tner to leave them with him for some time longer.

Goethe adds a short account of the progress of the experiments he now undertook as well as of his efforts to interest others in his discovery. He makes grateful reference to those who had brought him understanding, and who had been helpful to him through the exchange of thoughts. Among these, apart from Schiller, whom Goethe especially mentions, we find a number of leading anatomists, chemists, writers and philosophers of his time, but not a single one of the physicists then active in teaching or research. The 'Guild' took up an att.i.tude of complete disapproval or indifference, and so have things remained till a hundred years after his death, as Goethe himself prophesied.

One of the first systematic pieces of work which Goethe undertook in order to trace the cause of the Newtonian error was to go through Book I of Newton's Optics, sentence by sentence, recapitulate Newton's experiments and rearrange them in the order which seemed to him essential. In so doing he gained an insight which was fundamental for all future work, and often proved very beneficial in the perfecting of his own methods. His examination of the Newtonian procedure showed him that the whole mistake rested on the fact that 'a complicated phenomenon should have been taken as a basis, and the simpler explained from the complex'. Nevertheless, it still needed 'much time and application in order to wander through all the labyrinths with which Newton had been pleased to confuse his successors'.

It seems a small thing, and yet it is a great one, which Goethe, as the above description shows, discovered almost by chance. This is shown by the conclusions to which he was led in the systematic prosecutions of his discovery. An account of them is given in his Beitrage zur Optik,6 published in 1791, the year in which Galvani came before the public with his observations in the sphere of electricity.

Goethe describes in this book the basic phenomena of the creation of the prismatic colours, with particulars of a number of experiments so arranged that the truth he had discovered, contrary to Newton's view, comes to light through the very phenomena themselves. Only much later, in the year 1810, and after he had brought to a certain conclusion four years previously the researches which he had pursued most carefully the whole time, did he make public the actual masterpiece, Entwurf einer Farbenlehre.7 (An English translation of the didactic part appeared about ten years after Goethe's death.)

While leaving a more detailed description of the composition of Goethe's Entwurf for our next chapter, we shall here deal at once with some of the essential conclusions to which the reader is led in this book. As already mentioned, Goethe's first inspection of the colour-phenomenon produced by the prism had shown him that the phenomenon depended on the presence of a boundary between light and darkness. Newton's attempt to explain the spectrum out of light alone appeared to him, therefore, as an inadmissible setting aside of one of the two necessary conditions. Colours, so Goethe gleaned directly from the prismatic phenomenon, are caused by both light and its counterpart, darkness. Hence, to arrive at an idea of the nature of colour, which was in accord with its actual appearance, he saw himself committed to an investigation of the extent to which the qualitative differences in our experience of colours rests upon their differing proportions of light and darkness.

It is characteristic of Goethe's whole mode of procedure that he at once changed the question, 'What is colour?' into the question, 'How does colour arise?' It was equally characteristic that he did not, as Newton did, shut himself into a darkened room, so as to get hold of the colour-phenomenon by means of an artificially set-up apparatus.

Instead, he turned first of all to nature, to let her give him the answer to the questions she had raised.

It was clear to Goethe that to trace the law of the genesis of colour in nature by reading her phenomena, he must keep a look-out for occurrences of colours which satisfied the conditions of the Ur-phanomen, as he had learned to know it. This meant that he must ask of nature where she let colours arise out of light and darkness in such a way that no other conditions contributed to the effect.

He saw that such an effect was presented to his eye when he turned his gaze on the one hand to the blue sky, and on the other to the yellowish luminous sun. Where we see the blue of the heavens, there, spread out before our eyes, is universal s.p.a.ce, which as such is dark. Why it does not appear dark by day as well as by night is because we see it through the sun-illumined atmosphere. The opposite role is played by the atmosphere when we look through it to the sun. In the first instance it acts as a lightening, in the second as a darkening, medium.

Accordingly, when the optical density of the air changes as a result of its varying content of moisture, the colour-phenomenon undergoes an opposite change in each of the two cases. Whilst with increasing density of the air the blue of the sky brightens up and gradually pa.s.ses over into white, the yellow of the sun gradually darkens and finally gives way to complete absence of light.

The ur-phenomenon having once been discovered in the heavens, could then easily be found elsewhere in nature on a large or small scale-as, for instance, in the blue of distant hills when the air is sufficiently opaque, or in the colour of the colourless, slightly milky opal which looks a deep blue when one sees it against a dark background, and a reddish yellow when one holds it against the light. The same phenomenon may be produced artificially through the clouding of gla.s.s with suitable substances, as one finds in various gla.s.s handicraft objects.

The aesthetic effect is due to the treated gla.s.s being so fas.h.i.+oned as to present continually changing angles to the light, when both colour-poles and all the intermediate phases appear simultaneously. It is also possible to produce the ur-phenomenon experimentally by placing a gla.s.s jug filled with water before a black background, illuminating the jug from the side, and gradually clouding the water by the admixture of suitable substances. Whilst the brightness appearing in the direction of the light goes over from yellow and orange to an increasingly red shade, the darkness of the black background brightens to blue, which increases and pa.s.ses over to a milky white.

It had already become clear to Goethe in Italy that all colour-experience is based on a polarity, which he found expressed by painters as the contrast between 'cold' and 'warm' colours. Now that the coming-into-being of the blue of the sky and of the yellow of the sun had shown themselves to him as two processes of opposite character, he recognized in them the objective reason why both colours are subjectively experienced by us as opposites. 'Blue is illumined darkness - yellow is darkened light' - thus could he a.s.sert the urphenomenon, while he expressed the relation to Light of colours in their totality by saying: 'Colours are Deeds and Sufferings of Light.'

With this, Goethe had taken the first decisive step towards his goal - the tracing of man's aesthetic experience to objective facts of nature.

If we use the expressions of preceding chapters, we can say that Goethe, in observing the coloured ur-phenomenon, had succeeded in finding how from the primary polarity, Light-Dark, the opposition of the yellow and blue colours arises as a secondary polarity. For such an interplay of light and darkness, the existence of the air was seen to be a necessary condition, representing in the one case a lightening, in the other, a darkening element. That it was able to play this double role arose from its being on the one hand pervious to light, while yet possessing a certain substantial density. For a medium of such a nature Goethe coined the expression trubes Medium.

There seems to be no suitable word in English for rendering the term trube in the sense in which Goethe used it to denote the optical resistance of a more or less transparent medium. The following remarks of Goethe's, reported by his secretary Riemer, will give the reader a picture of what Goethe meant by this term, clear enough to allow us to use the German word. Goethe's explanation certainly shows how inadequate it is to translate trube by 'cloudy' or 'semi-opaque' as commentators have done. 'Light and Dark have a common field, a s.p.a.ce, a vacuum in which they are seen to appear. This s.p.a.ce is the realm of the transparent. Just as the different colours are related to Light and Dark as their creative causes, so is their corporeal part, their medium, Trube, related to the transparent. The first diminution of the transparent, i.e. the first slightest filling of s.p.a.ce, the first disposition, as it were, to the corporeal, i.e. the non-transparent - this is Trube.'8

After Goethe had once determined from the macrotelluric phenomenon that an interplay of light and darkness within Trube was necessary for the appearance of colour in s.p.a.ce, he had no doubt that the prismatic colours, too, could be understood only through the coming together of all these three elements. It was now his task to examine in what way the prism, by its being trube, brings light and darkness, or, as he also expressed it, light and shadow, into interplay, when they meet at a boundary.

We must remember that on first looking through the prism Goethe had immediately recognized that the appearance of colour is always dependent on the existence of a boundary between light and darkness - in other words, that it is a border phenomenon. What colours appear on such a border depends on the position of light and darkness in relation to the base of the prism. If the lighter part is nearer to the base, then blue and violet tints are seen at the border, and with the reverse position tints of yellow and red (Plate B, Fig. i). Along this path of study Goethe found no reason for regarding the spectrum-phenomenon as complete only when both kinds of border-phenomena appear simultaneously (let alone when - as a result of the smallness of the aperture through which the light meets the prism - the two edges lie so close that a continuous band of colour arises). Hence we find Goethe - unlike Newton - treating the two ends of the spectrum as two separate phenomena.

In this way, the spectrum phenomenon gave Goethe confirmation that he had succeeded in expressing in a generally valid form the law of the origin of the blue and the yellow colours, as he had read it from the heavens. For in the spectrum, too, where the colour blue appears, there he saw darkness being lightened by a s.h.i.+fting of the image of the border between light and dark in the direction of darkness; where yellow appears, he saw light being darkened by a s.h.i.+fting of the image in the direction of light. (See the arrow in Fig. i.)

In the colours adjoining these - indigo and violet on the blue side, orange and red on the yellow side - Goethe recognized 'heightened'

modifications of blue and yellow. Thus he had learnt from the macro-telluric realm that with decreasing density of the corporeal medium, the blue sky takes on ever deeper tones, while with increasing density of the medium, the yellow of the sunlight pa.s.ses over into orange and finally red. Prismatic phenomenon and macrotelluric phenomenon were seen to correspond in this direction, too.

Faithful to his question, 'How does colour arise?' Goethe now proceeded to investigate under what conditions two borders, when placed opposite each other, provide a continuous band of colour - that is, a colour-band where, in place of the region of uncoloured light, green appears. This, he observed, came about if one brought one's eye, or the screen intercepting the light, to that distance from the prism where the steadily widening yellow-red and the blue-violet colour-cones merge (Fig. ii).9 Obviously, this distance can be altered by altering the distance between the two borders. In the case of an extremely narrow light-s.p.a.ce, the blue and yellow edges will immediately overlap. Yet the emergence of the green colour will always be due to a union of the blue and yellow colours which spread from the two edges. This convinced Goethe that it is inadmissible to place the green in the spectrum in line with the other colours, as is customary in the explanation of the spectrum since Newton's time.

This insight into the relation of the central colour of the continuous spectrum to its other colours still further strengthened Goethe's conviction that in the way man experiences nature in his soul, objective laws of nature come to expression. For just as we experience the colours on the blue side of the spectrum as cold colours, and those on the yellow side as warm colours, so does green give man the impression of a neutral colour, influencing us in neither direction.

And just as the experience of the two polar colour-ranges is an expression of the objective natural law behind them, so too is the experience of green, the objective conditions of whose origin give it a neutral position between the two. With this it also became clear why the vegetative part of the plant organism, the region of leaf and stem formation, where the light of the sun enters into a living union with the density of earthly substance, must appear in a garment of green.

Having in this way found the clue to the true genesis of the spectrum, Goethe could not fail to notice that it called for another - a 'negative' spectrum, its polar opposite - to make the half into a whole. For he who has once learnt that light and darkness are two equally essential factors in the birth of colour, and that the opposing of two borders of darkness so as to enclose a light is a 'derived'

(abgeleitet) experimental arrangement, is naturally free to alter the arrangement and to supplement it by reversing the order of the two borders, thus letting two lights enclose a darkness between them.

If one exposes an arrangement like this to the action of the prism, whose position has remained unchanged, colours appear on each of the two edges, as before, but in reverse order (Fig. iii). The spectral phenomenon now begins at one side with light blue and pa.s.ses into indigo and violet, with uncoloured darkness in the centre. From this darkness it emerges through red and pa.s.ses through orange to yellow at the other end.

Again, where the two interior colour-cones merge, there an additional colour appears. Like green, it is of a neutral character, but at the same time its quality is opposite to that of green. In Newtonian optics, which a.s.sumes colour to be derived from light only, this colour has naturally no existence. Yet in an optics which has learnt to reckon with both darkness and light as generators of colour, the complete spectrum phenomenon includes this colour equally with green. For lack of an existing proper name for it, Goethe termed it 'pure red' (since it was free from both the blue tinge of the mauve, and the yellow tinge of the red end of the ordinary spectrum), or 'peach-blossom'

(pfirsichblut), or 'purple' (as being nearest to the dye-stuff so called by the ancients after the mollusc from which it was obtained).10

It needs only a glance through the prism into the sunlit world to make one convinced of the natural appearing of this delicate and at the same time powerfully luminous colour. For a narrow dark object on a light field is a much commoner occurrence in nature than the enclosing by two broad objects of a narrow s.p.a.ce of light, the condition necessary for the emergence of a continuous colour-band with green in the middle. In fact, the spectrum which science since the time of Newton regards as the only one, appears much more rarely among natural conditions than does Goethe's counter-spectrum.

With the peach-blossom a fresh proof is supplied that what man experiences in his soul is in harmony with the objective facts of nature. As with green, we experience peach-blossom as a colour that leaves us in equilibrium. With peach-blossom, however, the equilibrium is of a different kind, owing to the fact that it arises from the union of the colour-poles, not at their original stage but in their 'heightened' form. And so green, the colour of the plant-world harmony given by nature, stands over against 'purple', the colour of the human being striving towards harmony. By virtue of this quality, purple served from antiquity for the vesture of those who have reached the highest stage of human development for their time. This characteristic of the middle colours of the two spectra was expressed by Goethe when he called green 'real totality', and peach-blossom 'ideal totality'.

From this standpoint Goethe was able to smile at the Newtonians. He could say that if they persisted in a.s.serting that the colourless, so-called 'white' light is composed of the seven colours of the ordinary spectrum - red, orange, yellow, green, blue, indigo, violet - then they were in duty bound to maintain also that the colourless, 'black' darkness is composed of the seven colours of the inverted spectrum - yellow, orange, red, purple, violet, indigo, blue.

Despite the convincing force of this argument, the voice of the Hans Andersen child speaking through Goethe failed to gain a hearing among the crowd of Newtonian faithful. So has it been up to the present day - regardless of the fact that, as we have shown, modern physics has reached results which make a contradiction of the Newtonian concept of the mutual relation of light and colour no longer appear so heretical as it was in Goethe's time.